x1,y1,x2,y2=list(map(float,input().split()))

d=((x1-x2)**2+(y1-y2)**2)**0.5

print(d) x1,y1,x2,y2=list(map(float,input().split())) x1 list(map(float,input().split())) list map(float,input().split()) map float input().split() ().split () input split y1 x2 y2 d=((x1-x2)**2+(y1-y2)**2)**0.5 d ((x1-x2)**2+(y1-y2)**2)**0.5 (x1-x2)**2+(y1-y2)**2 (x1-x2)**2 x1-x2 x1 x2 2 (y1-y2)**2 y1-y2 y1 y2 2 0.5 print(d) print d y2=list(map(float,input().split())) list(map(float,input().split())) y2 d=((x1-x2)**2+(y1-y2)**2)**0.5 ((x1-x2)**2+(y1-y2)**2)**0.5 d x1,y1,x2,y2=list(map(float,input().split())) list(map(float,input().split())) x1 x2,y2=list(map(float,input().split())) list(map(float,input().split())) x2 y1,x2,y2=list(map(float,input().split())) list(map(float,input().split())) y1
x1,y1,x2,y2=list(map(float,input().split()))

d=((x1-x2)**2+(y1-y2)**2)**0.5

print(d)